/*
 * Copyright 2014 mango.jfaster.org
 *
 * The Mango Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package org.jfaster.mango.jdbc;

import org.jfaster.mango.exception.jdbc.*;

import java.sql.SQLException;
import java.util.HashSet;
import java.util.Set;

/**
 * @author ash
 */
public class SQLStateSQLExceptionTranslator extends AbstractFallbackSQLExceptionTranslator {

    private static final Set<String> BAD_SQL_GRAMMAR_CODES = new HashSet<String>(8);

    private static final Set<String> DATA_INTEGRITY_VIOLATION_CODES = new HashSet<String>(8);

    private static final Set<String> DATA_ACCESS_RESOURCE_FAILURE_CODES = new HashSet<String>(8);

    private static final Set<String> TRANSIENT_DATA_ACCESS_RESOURCE_CODES = new HashSet<String>(8);

    private static final Set<String> CONCURRENCY_FAILURE_CODES = new HashSet<String>(4);


    static {
        BAD_SQL_GRAMMAR_CODES.add("07");	// Dynamic SQL error
        BAD_SQL_GRAMMAR_CODES.add("21");	// Cardinality violation
        BAD_SQL_GRAMMAR_CODES.add("2A");	// Syntax error direct SQL
        BAD_SQL_GRAMMAR_CODES.add("37");	// Syntax error dynamic SQL
        BAD_SQL_GRAMMAR_CODES.add("42");	// General SQL syntax error
        BAD_SQL_GRAMMAR_CODES.add("65");	// Oracle: unknown identifier

        DATA_INTEGRITY_VIOLATION_CODES.add("01");	// Data truncation
        DATA_INTEGRITY_VIOLATION_CODES.add("02");	// No data found
        DATA_INTEGRITY_VIOLATION_CODES.add("22");	// Value out of range
        DATA_INTEGRITY_VIOLATION_CODES.add("23");	// Integrity constraint violation
        DATA_INTEGRITY_VIOLATION_CODES.add("27");	// Triggered data change violation
        DATA_INTEGRITY_VIOLATION_CODES.add("44");	// With check violation

        DATA_ACCESS_RESOURCE_FAILURE_CODES.add("08");	 // Connection exception
        DATA_ACCESS_RESOURCE_FAILURE_CODES.add("53");	 // PostgreSQL: insufficient resources (e.g. disk full)
        DATA_ACCESS_RESOURCE_FAILURE_CODES.add("54");	 // PostgreSQL: program limit exceeded (e.g. statement too complex)
        DATA_ACCESS_RESOURCE_FAILURE_CODES.add("57");	 // DB2: out-of-memory exception / database not started
        DATA_ACCESS_RESOURCE_FAILURE_CODES.add("58");	 // DB2: unexpected system error

        TRANSIENT_DATA_ACCESS_RESOURCE_CODES.add("JW");	 // Sybase: internal I/O error
        TRANSIENT_DATA_ACCESS_RESOURCE_CODES.add("JZ");	 // Sybase: unexpected I/O error
        TRANSIENT_DATA_ACCESS_RESOURCE_CODES.add("S1");	 // DB2: communication failure

        CONCURRENCY_FAILURE_CODES.add("40");	// Transaction rollback
        CONCURRENCY_FAILURE_CODES.add("61");	// Oracle: deadlock
    }


    @Override
    protected DataAccessException doTranslate(String sql, SQLException ex) {
        String sqlState = getSqlState(ex);
        if (sqlState != null && sqlState.length() >= 2) {
            String classCode = sqlState.substring(0, 2);
            if (logger.isDebugEnabled()) {
                logger.debug("Extracted SQL state class '" + classCode + "' from value '" + sqlState + "'");
            }
            if (BAD_SQL_GRAMMAR_CODES.contains(classCode)) {
                return new BadSqlGrammarException(sql, ex);
            }
            else if (DATA_INTEGRITY_VIOLATION_CODES.contains(classCode)) {
                return new DataIntegrityViolationException(buildMessage(sql, ex), ex);
            }
            else if (DATA_ACCESS_RESOURCE_FAILURE_CODES.contains(classCode)) {
                return new DataAccessResourceFailureException(buildMessage(sql, ex), ex);
            }
            else if (TRANSIENT_DATA_ACCESS_RESOURCE_CODES.contains(classCode)) {
                return new TransientDataAccessResourceException(buildMessage(sql, ex), ex);
            }
            else if (CONCURRENCY_FAILURE_CODES.contains(classCode)) {
                return new ConcurrencyFailureException(buildMessage(sql, ex), ex);
            }
        }
        return null;
    }

    /**
     * Gets the SQL state code from the supplied {@link SQLException exception}.
     * <p>Some JDBC drivers nest the actual exception from a batched update, so we
     * might need to dig down into the nested exception.
     * @param ex the exception from which the {@link SQLException#getSQLState() SQL state}
     * is to be extracted
     * @return the SQL state code
     */
    private String getSqlState(SQLException ex) {
        String sqlState = ex.getSQLState();
        if (sqlState == null) {
            SQLException nestedEx = ex.getNextException();
            if (nestedEx != null) {
                sqlState = nestedEx.getSQLState();
            }
        }
        return sqlState;
    }

}
